Historically motorized treadmills have been designed to enable running at high speeds, in contrast to walking at much slower speeds. The demands to support running speeds require a heavy motor and base, and a longer belt that allows for longer step lengths during running. The belt speeds required for running require the large motor and heavy flywheel to maintain speed while under load. The long belt runs between two sidewalls of the base, each of which is wide enough for a runner's foot so that the runner can jump off the belt if it gets moving too fast or the runner loses his balance. A treadmill for running typically has a chest-high framework extending upwards from the front of the base, upon which a display is mounted for the runner to view while running, and a housing under the display for enclosing the motor. Many also have handgrips or arms that extend from the frame at chest height a short distance in front of the runner's body, but that do not extend to the side of the runner to avoid encumbering the runner's arms while they are pumping. These requirements cause all currently available motorized treadmills to be large, heavy and therefore not easily portable.
While there are health benefits to running on a treadmill, many people prefer to—or need to—walk instead of run. For those suffering gait restrictions such as weak legs or poor balance, people commonly use a walker to aid in walking. Typically a walker is an open framework of four posts which form two side supports with handgrips at about hip height, and a front crossbar that connects the two side rails, open at the rear so that the user is surrounded on three sides by the framework. To walk, the user grips the handgrips and supports some or most of his weight with his arms while moving his feet forward a step. Then he picks up the walker and moves it forward, supports his weight with his arms, and steps forward again. However, using a walker to walk any meaningful distance requires that the user physically leave the room he is in, which can be difficult in certain situations, thereby decreasing the likelihood the user will actually walk more than a few steps. A treadmill designed for walking, preferably that is also lightweight and easily movable, would provide a safe walking environment for patients in a hospital room; convalescents and others needing rehabilitation; in luxury hotels for customers who prefer to walk in their room instead of the on-site gym or unfamiliar neighborhood; for desk workers and those with other sedentary jobs; for therapists who treat different patients in different locations; and for those who would like to gain general health benefits from walking without having to roam a large area. Therefore, there is a need for a treadmill designed for walking that encourages walking and that is not constrained by the demands of a device for running.
Therefore, it is an object of this invention to provide a treadmill for walking instead of running. It is another object to provide a treadmill for walking that is safe for walkers. It is another object to provide a treadmill for walking that is compact and relatively lightweight for easy portability.